The present invention relates to screeds for pavers, and more particularly to paver screeds having tamper bars and devices for heating the tamper bars.
Paving machines or pavers generally include a mobile frame, a screed arranged at the rear (i.e., with respect to the "laying" or paving direction) of the frame, and a distributor auger located between the frame and screed. The screed is typically articulated on the paver frame by means of a pair of tension arms, so that the screed "floats" on the paving material being laid by the paver.
Floating screeds of this type are known, such as for example in EP 0,641,887 Al. The screed assembly disclosed in the EP 0,641,887 Al patent includes a tamper bar configured to be movable in upward and downward directions and arranged in front (i.e, with respect to the paving direction) of a baseplate so as to extend transversely to the paving direction. The tamper bar is capable of being driven by means of an eccentric drive and is electrically heatable via a heating element, for example a resistance heating bar. The tamper bar includes at least one wearing part, in other words the member that performs the compacting, and at least one carrier part, such as for example, one or more connecting rods. Further, the tamper bar includes at least one channel for receiving the heating element, the channel being formed in the wearing part, in the carrier part or between the wearing part and carrier part. The heating element is located in the channel and is thus moved up and down together with the tamper bar when the screed is in operation.
To provide electricity to the heating element, "supply lines" in the form of wires, cables, etc., extend between the heating element on the tamper and an electrical current source located on the screed or otherwise on the paver. Due to the fact that these wires or cables must move with the tamper as it reciprocates upwardly and downwardly, frequent operating faults occur with these supply lines.
The object of the present invention is to provide a screed for a paver in which the device for heating of the tamper bar is designed to be less susceptible to faults.